Questions tagged [beam]
Questions about the theory and applications of structural elements designed to resist bending.
2
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2answers
46 views
Why two identical beams without being pinned together will share half of the bending moments?
As shown above, two identical rectangular beams are placed and NO pinned together. I know each beam has its own neutral surface but why they carry half of the bending moments? I thought the bending ...
1
vote
1answer
29 views
What's the second moment of a T beam with a heel? [closed]
The second moment of area of a rectangle is $I_{yy} = \dfrac{bh^2}{12}$
b : base
h : height
What is the second moment of area of a T beam like this one?
1
vote
0answers
24 views
How much (uniformly distributed) weight can this L beam support without bending? [closed]
As you can see in the picture, the L beam is 1in x 1/2in x 1/8in thick x 72in long and is made of ASTM A36 steel. It's bolted onto a vertical upright on both ends.
What is the maximum uniformly ...
2
votes
0answers
26 views
Abaqus Failure for I-Beam Section in Major direction only
For my 4th year dissertation in Civil Engineering I've got to investigate the difference between BS5950, Eurocode 3 and ABAQUS failures. The only thing is, in the BS5950 and Eurocode 3 the failure can ...
0
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0answers
26 views
Beam Defelction Using Macaulay Theorem
I have a simply supported beam and am trying to work out the deflection using Macaulay's Theory, is it possible to verify my results, I feel they are far out, and can not see where the error lies. ...
0
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0answers
37 views
Beam analysis - relating deflection equation to pressure force
From regular beam deflection equation and $f=kx$, I ended up getting
$$k = \dfrac{4Ebh^3}{L^3}$$
where $k$ is stiffness, $E$ is modulus, $b$ is width, $h$ is thickness, $L$ is the length. and the ...
0
votes
2answers
44 views
Resulting torque on the cross section
I have trouble solving part A of the question. I thought the resulting torque would just be 10k * L of the beam.
0
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1answer
56 views
Which container orientation, if any, can hold more weight?
These are cross sections of identical shipping containers, except one is rotated 45 degrees. The cross sections are squares, 3 meters to a side. I drew dashed lines to show where they're suspended by ...
0
votes
1answer
39 views
Neutral axis in canteliver beam at support
First, I thought the neutral axis would just be the y bar which can be obtained from the centroid of the cross-section but is different. I have tried letting the net moment at the wall = 0 and the ...
0
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0answers
22 views
Can we have flange (T Beam) Reinforced Concrete with double reinforcement?
Can we have a T concrete Beam with double reinforcement, or the reinforcement must be just located at the bottom of Beam? (considering we have a positive moment)
If Mu > ∅Mn, T Beam must be double ...
1
vote
1answer
74 views
Should one use multiple elements through the thickness with multiple materials?
To get realistic results from a FEM calculation, it is common (or so I've been taught by someone who may not be up to date) to use at least four or five elements through the thickness of a beam or ...
2
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0answers
35 views
How to add Beam cross section properties to imported mesh in Ansys?
Ansys Workbench 17.1
I have a mesh that was imported from Abaqus into Ansys but the beam cross section data is missing. As a result the structural model omits the beam elements.
How do I access the ...
2
votes
2answers
119 views
Deflection of a cantilever beam composed of separate (not bonded) planks
In the case of a simple cantilever beam having a uniform shape and being loaded at its end - the calculation of the deflection at any point along the beam is well known.
What happens if we split it ...
2
votes
2answers
32 views
Is is possible to use singularity function to expresse the horizontal forces ?
I know how to translate torques and vertical forces into singularity functions, but may i also express the horizontal forces with singular function? if yes then what would be that expression?
Here ...
2
votes
1answer
53 views
Shear forces along a beam using singularity functions
$\newcommand{\a}[1]{\langle#1\rangle}$
As you can see, the left end of the beam is fixed, and a distributed load is applied to the beam. I calculated the shear forces by conventional means, but when I ...
2
votes
1answer
84 views
Bending equation and max deflection of UDL and multiple point loads
I have a beam, simply supported with 2 points loads and 2 UDLs. The loads are symmetric about the centre of the beam.
I've tried to derive an expression for the moment along the beam and then via 2 ...
0
votes
2answers
35 views
Loadcell / strain gauge sizing for a joist
I am looking to use some load cells (foil based type) to detect presence for home automation within in a room. I was looking to mount some loadcells to the joists for the floor (UK Based house so ...
2
votes
2answers
86 views
What exactly is the thin wall assumption in regards to beam cross sections?
What does it mean with respect to calculating stresses on a beam undergoing loading and when should it be applied?
2
votes
1answer
60 views
Timoshenko Beam Theory for Quasistatic Cantilever Beam: Shear Term
I'm trying to determine the effect of shearing force on the deflection of a quasistatic cantilever beam. In his book, Theory of Elasticity, Timoshenko added the following term to the deflection:
$$\...
2
votes
2answers
37 views
How to find a beam for my (simple) application
I have a spanof 9m that I bridge with a (as yet unspecified) beam. From this beam hangs a load (a pipeline), right in the middle, of 4.295 kN. The beam is simply supported. I want to use an IPE steel ...
2
votes
2answers
79 views
Ceiling mounted punching bag without compromising structure or floor above
This question is regarding the safest way of installing a heavy punching bag of 100 lbs from the basement ceiling. Above the basement ceiling is a wood floor. The goal is to sleep soundly at night ...
0
votes
1answer
51 views
How does the superposition principle relate to Bernoulli-Euler and Timoshenko beam theory? [closed]
I have a shaft with a bearing in each end, and a large eccentric mass covering the entire "free length" of the shaft.
The attachment of the eccentric mass is done using heat shrinking.
Without ...
1
vote
3answers
350 views
Transfering moment through internal hinge
My professor says, the internal hinge can not transfer moment:
But can we calculate $\Sigma M_A=0$ for whole beam ( without cutting it or something) this way?:
$\Sigma M_A=0 ===\Rightarrow M_A+(D_y ...
1
vote
1answer
49 views
Base Support for a Tree house
I am building a tree house in my backyard and it is going to be relatively simple. There are no parts that require drilling into the tree. The whole house is propped up by four 4x4 wood supports. I'm ...
4
votes
3answers
65 views
Natural frequencies of an orthotropic bending beam with circular cross-section
I am trying to find an expression for the natural frequencies of an orthotropic bending beam with a circular cross-section. I have tried searching for some literature on this, but have so far been ...
4
votes
2answers
488 views
Multiple Varying cross section beam deflection
How do we calculate the deflection of a cantilever with two or three cross-sections, and different forces acting at the end of each section?
1
vote
1answer
67 views
Beam Span for Outdoor Shelter [closed]
I'm building an outdoor shelter and I'm wondering what would be:
The maximum beam span for the type of wood/material used such it can support the roof weight and not sag in the middle,
Suggestions on ...
3
votes
1answer
117 views
Skewing of joints using virtual work
Given ist the following framework:
$$E=210 \frac{\text{kN}}{\text{mm}^2}$$
$$ EA \to \infty $$
$$ I_1 = 80000\text{cm}^4 $$
$$ \frac{I_1}{I_2} = \frac{3}{4} $$
$$ I_3=I_1 $$
Using the principle of ...
-1
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2answers
76 views
Engineering mechanics(statics) [closed]
I don’t get how to get the answer to part e. Should we assume reactions at A and B in all three figures are same? If so, why?
0
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0answers
67 views
Determining Elastic Equation of Beam with Linearly Distributed Load
I'm trying to solve this question, but I'm not sure where to start.
Typically, to solve this type of problem, I would find the vertical support reaction at R $\left(\dfrac{w_0 L}{24}\right)$, then ...
2
votes
2answers
362 views
Beam deformation under trapezoidal load
Can somebody help me find the equation for the deformation of a simply supported beam under trapezoidal load (with intensity Q1 and Q2, at starting point X1 and end point X2)?
I am trying to find it ...
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vote
0answers
437 views
Equivalent spring of beam supported by springs
My professor gave us yesterday a problem to calculate the equivalent spring of the system shown in the attached figure. The problem: a cantilever beam supported by two springs $k_1$ and $k_2$ located ...
3
votes
3answers
37 views
Support columns inside metal tubing
Does structural metal tubing (e.g., either as HSS, or in space frames, or even motorcycle/bicycle frames) ever come with any small metal rods or columns inside of the tubing itself?
While it might ...
1
vote
0answers
394 views
Simply Supported beam with multiple point loads and distributed load [closed]
How can I solve this problem using FEM (longhand calculation)? I want to find deflections at each load point. This is not a homework problem. This is related to a project that I and my brother is ...
1
vote
1answer
824 views
Transfer of moments in beams with internal hinges
We have a beam with 1 internal hinge just like the picture. We know the internal hinge can not transfer moments between AB and BD. We know the 30 kN force makes some moments on BD & AB. If B (...
4
votes
1answer
73 views
Why are steel I-beams mostly symmetrical?
From what I understand most types of steel are strong both in tension and compression, yet they are still usually significantly stronger in tension. Suppose a common I-beam supported on both ends and ...
2
votes
2answers
955 views
Are the points of inflection and contraflexure the same?
In theory of bending of beams, often these terms are used. There are no clear definition present. Most of them contradicting. Which of the property(bending moment and shear force) is zero in which ...
0
votes
1answer
113 views
How to deal with inverse distributed load ramp starts and ends somewhere along the beam?
I know how to solve it by moment line methode but i want to use singularity function here and i'm very confused. My strategy consist of writing the correspond singularity function for each element but ...
3
votes
3answers
68 views
Why in the construction of power transmission towers , the rods are hinged oblique? [closed]
I know if a rod is hinged at its two ends and if there is no load act upon it along its length then the forces exist only along its length but i don't see how this characteristic comes into play ?
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0answers
42 views
How to design a shelving unit out of McMaster Carr Struts? [closed]
I apologize for the complete beginner question.
I'm an Undergraduate Research Assistant trying to design a shelving 8'tall by 10' Long, 4' wide shelving unit to support about 200 lbs. I'm designing ...
0
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0answers
383 views
Differentiate between rectangular beam and flange beam
How to differentiate between rectangular beam and flange beam ??? In the question below , the answer provided is flange beam , I'm wondering can i design it as rectangular beam
Since there's no clue ...
5
votes
1answer
86 views
Deformation of two perpendicular beams with parabolic properties
I want to calculate the deformation of the following structure:
I have numbered the vertical beam 1 and the horzontal beam 2. The hight of beam 2 is given by:
$h(x)=h\sqrt{1-x/L_2}$
So I thought I ...
1
vote
0answers
59 views
Plate bending boundary conditions
A plate with length 2L is placed on supports at x = L/2 and x = - L/2. The plate is deforming elastically under its own weight (maximum displacement bowing up at x = $0$). Both ends of the plate are ...
2
votes
4answers
75 views
Moment and Torque at a Single Point
As far as I know, moments/torques occur when forces applied are not in line. However, I often see moments/torques being applied at a single point in free body diagrams.
How can moment/torque be ...
0
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2answers
3k views
how to solve internal hinge problem with loading given on hinge [closed]
how to solve internal hinge problem with loading given on hinge
0
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1answer
411 views
Why are the support reactions of the two pin-connected members different?
Can someone please explain why the support at C does not have a vertical reaction force while the support at E has?
Doesn't the support at C have the same kind of pin connection as the support at E?
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0answers
152 views
How can I use the bending stiffness of corrugated cardboard to determine maximum stacking heights of pallets loaded with glass bottles?
I am doing a project at the moment which involves improving the packaging operation at work. Right now I am looking at ways to improve packaging selection based on engineering principles, rather than ...
3
votes
1answer
56 views
Is there a need to consider the moment generated by horizontal water pressure in a pool?
Suppose there's a pool which is supported by 4 beams (Perimeter beams)and 4 columns. When designing the beam should we consider the moment generated due to the horizontal water pressure? (I'm using ...
1
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1answer
86 views
Structural engineering: Would I need a beam for this? [closed]
If I was designing a simple gabled house with a 21 ft vaulted ceiling as the peak of the roof, and the house was about 32 ft x 40 ft with no load bearing walls (other than the 4 exterior walls)... ...
2
votes
1answer
880 views
Reinforcing beam and slab with correct steel bar structure
This question might look silly. I am not knowing the correct engineering terms to use in this question. I am trying to explain using the words what I know in English.
We have been hired some ...
